libvips/examples/progress-cancel.c
2022-09-09 10:14:59 +01:00

79 lines
1.8 KiB
C

/* Show progress feedback and computation cancel.
*
* compile with
*
* gcc -g -Wall progress-cancel.c `pkg-config vips --cflags --libs`
*/
#include <stdio.h>
#include <vips/vips.h>
#include <errno.h>
void
preeval_callback( VipsImage *image, VipsProgress *progress, void* pdata )
{
printf( "preeval_callback:\n" );
}
void
eval_callback( VipsImage *image, VipsProgress *progress, void* pdata )
{
printf( "eval_callback: percent = %d\n", progress->percent );
if( progress->percent >= 25 ) {
printf( "calling vips_image_set_kill() ...\n" );
vips_image_set_kill( image, TRUE );
}
}
void
posteval_callback( VipsImage *image, VipsProgress *progress, void* pdata )
{
printf( "posteval_callback: finished in %.3gs\n",
g_timer_elapsed( progress->start, NULL ) );
}
int
main( int argc, char **argv )
{
VipsImage *image;
VipsImage *out;
void *output;
size_t output_length;
if( VIPS_INIT( argv[0] ) )
vips_error_exit( NULL );
if( argc != 3 )
vips_error_exit( "usage: %s INPUT-FILE OUTPUT-FILE", argv[0] );
if( !(image = vips_image_new_from_file( argv[1],
"access", VIPS_ACCESS_SEQUENTIAL,
NULL )) )
vips_error_exit( NULL );
if( vips_resize( image, &out, 0.5, NULL ) )
vips_error_exit( NULL );
vips_image_set_progress( out, TRUE );
g_signal_connect( out, "preeval",
G_CALLBACK( preeval_callback ), NULL );
g_signal_connect( out, "eval",
G_CALLBACK( eval_callback ), NULL );
g_signal_connect( out, "posteval",
G_CALLBACK( posteval_callback ), NULL );
output = NULL;
if( vips_image_write_to_buffer( out, argv[2], &output, &output_length,
NULL ) )
printf( "error return from vips_image_write_to_buffer()\n" );
g_object_unref( out );
g_object_unref( image );
if( output )
g_free( output );
vips_shutdown();
return 0;
}